The present invention relates generally to communication networks, and more particularly to a communication network, computer program and method for enabling a wireless enabled information processing device, such as a portable computer or personal digital assistant, to emulate a cellular communications terminal, such as a GSM (Global System for Mobile communications) or 3G (third generation) cellular telephone.
The use of wireless communication networks and devices, including cellular telephones and portable computers or network access appliances, has increased exponentially in recent years. Many individuals now carry a cellular telephone, and a portable computer or a similar information processing device, such as a laptop computer, notebook computer or personal digital assistant (PDA), adapted to access a wireless local area network (WLAN) or the Internet via a radio link. Maintaining and carrying two devices that perform essentially the same function, i.e., provide wireless access to a communication network, presents a number of difficulties or disadvantages. First is the expense associated with purchasing the two separate devices, and the expense associated with subscribing to separate services for both devices. There is also the weight or bulk of the devices themselves. Although cellular telephones and portable computers or PDAs are decreasing in size, they are still somewhat bulky.
One possible solution to the above problem is a combination portable computer/telephone having dual radio functionality, including a first radio, such as a radio compatible with one or more high performance wireless communication standards, including, for example, Institute of Electrical and Electronics Engineers 802. 11, high performance local area network (HiperLAN) or Bluetooth, for accessing a computer network, and a second GSM or 3G radio transceiver for accessing a cellular network. However, this approach is not wholly satisfactory for a number of reasons. First the integration of two radios into a single combination device adds to the complexity of the device and therefore would probably not result in substantial savings in cost or weight. In fact, the integration of two radios in a single device, would necessarily require additional components, thereby adding to the cost and complexity of the devices. Moreover, because the two radios operate in vastly different frequency ranges, it is not necessarily the case that a single service provider would be able to provide service in both bands, and therefore there may not be any savings in operating or service costs.
There is yet another problem with conventional cellular telephones and with the above combination device. Wide spread use of cellular telephones, particularly in urban areas and along major travel corridors has led to an overload condition with congestion in the available licensed frequency bands oftentimes resulting in delays, denial of services, and degraded service.
Another approach to solving the above problems is the use of voice over an Internet Protocol network (VoIP) with a WLAN. In this approach voice information is xe2x80x98packetizedxe2x80x99 and transmitted from a portable computer or wireless device to an access point connected to a wired local area network or the Internet. This approach is also not wholly satisfactory for a number of reasons. First, the portable computer lacks the ability to provide many of the services commonly expected with cellular telephones, including supplementary and value-added services such as call waiting, call-forwarding, call-conferencing and short message service. Second, while this approach might work well for a small, privately owned WLAN, traffic over public IP networks, such as the Internet, which would necessarily interconnect the access points, would likely cause problems with loss of packets, prioritization of packets, delay of packets and errors in packets. This in turn would result in an unacceptably degraded service.
Accordingly, there is a need for an apparatus and method capable of providing both wireless voice and data communication. It is desirable that the apparatus be less expensive, less complex, and weigh less or have less bulk than a separate cellular telephone and portable computer or other information processing device combined. It is also desirable that the apparatus be compatible with standardized private WLANs, and public cellular networks and Internet infrastructures. It is further desirable that the apparatus provide voice communication having a quality of service the same as or superior to that provided by single purpose GSM network or 3G network cellular telephones.
The system and method of the present invention provides these and other advantages over the prior art.
It is an object of the present invention to provide a communication system or network and method for enabling information processing devices, such as portable computers or personal digital assistants (PDAs), to communicate with telephones of private and public networks via an access point of a wireless local area network (WLAN).
It is a further object of the present invention to provide a client computer program or software capable of being downloaded into an information processing device having access to a WLAN to enable the information processing device to communicate with telephones of private and public networks via the access point of the WLAN.
In one aspect, the invention is directed to an information processing device capable of emulating a cellular communications terminal, such as a cellular telephone. Generally, the information processing device includes: (i) a transceiver capable of communicating with an access point of a WLAN; (ii) a computer readable memory; (iii) a processor capable of executing instructions of a computer program stored in the computer readable memory; and (iv) a computer program stored in the computer readable memory, the computer program having program code for enabling the information processing device to emulate a cellular communications terminal. Generally, the communications terminal emulated is a voice terminal, and the computer program further includes program code for marking or identifying packets containing voice information or voice packets to the access point. Preferably, the computer program further includes program code to enable the information processing device to emulate any one of a number of different telephones including: CDMA telephones; Global System for Mobile communications (GSM) cellular telephones; and third generation (3G) cellular telephones. More preferably, the computer program further includes program code to enable the information processing device to emulate a particular model of cellular telephone manufactured by a particular manufacturer.
In one embodiment, the information processing device further includes a subscriber identity module (SIM) card and an adapter that enables it to communicate with and function in a public or private cellular network. Alternatively, the information processing device further includes at least one virtual identity module with subscriber identification and security information stored in the computer readable memory to enable it to communicate with and function in a public or private cellular network.
In another embodiment, the computer program includes program code to enable the information processing device to control supplementary services and/or value added services provided by the public network or private network. Supplementary services controlled by the computer program can include: Voice Group Call Service; Voice Broadcast Service; Service definition Line Identification Supplementary Services; Call Forwarding Supplementary Services; Call Waiting and Call Hold Supplementary Services; Multiparty call conferencing; Closed User Group Supplementary Services; Advice of Charge Supplementary Services; Call Barring Supplementary Services; Unstructured Supplementary Service Data; Explicit Call Transfer; Completion of Calls to Busy Subscriber; Short Message Service; and Follow Me. Value-added services controlled by the computer program can include e-mail, calender, and wireless inventory.
In another aspect, the invention is directed to a communication network capable of operating with the information processing device configured and enabled as described above. Generally, the communication network further includes a public network having a public wireless network, and a private network having a switch through which the private network is coupled to the public network, and a WLAN with at least one access point.
Preferably, the WLAN is further coupled to an internet protocol (IP) network, and the access point further includes a computer readable memory; a processor capable of executing instructions of a computer program stored in the computer readable memory; and a packet routing program stored in the computer readable memory. The packet routing program includes program code to enable the access point to route voice packets to the switch over a first communication path, and packets not identified as voice packets to the IP network over a second communications path. Thus, enabling a user of the information processing device to simultaneously engage in voice communication with a terminal coupled to the public network, and data communication with a terminal coupled to the IP network. More preferably, the switch further includes a computer readable memory; a processor capable of executing instructions of a computer program stored in the computer readable memory; and a converter program stored in the computer readable memory to enable the switch to convert voice packets received from the information processing device to signals compatible with those used in the public network. In one version of this embodiment, the switch is a part of a private cellular network. Optionally, the public network further includes a public switched telephone network (PSTN), the private network further includes a private branch exchange (PBX), and the terminal emulator program, packet routing program and converter program are adapted to enable the information processing device to communicate with telephones coupled to the private cellular network, the PBX, the PSTN, and the public cellular network.
In yet another aspect, the invention is directed to a computer program product for use in conjunction with a WLAN enabled information processing device. Generally, the computer program is a terminal emulator program for enabling the information processing device to emulate a cellular communication terminal, and includes program code for: (i) emulating a telephone-type keypad; (ii) taking in information from the keypad; (iii) encapsulating information from the keypad into packets compatible with the access point of the WLAN; (iv) transmitting packets to establish a session with the access point; (v) taking in an audible signal or voice information from a microphone in or connected to the information processing device; (vi) encapsulating the voice information from the microphone into packets containing voice information or voice packets compatible with the access point of the WLAN; (vii) transmitting the voice packets to the access point; (viii) converting the voice packets received in the access point in to packets or signals compatible with the public or private wireless networks; (ix) receiving voice packets from the access point; and (x) converting the received voice packets into an audible signal or voice information to engage in voice communication with a telephone coupled to the private or public network.
In one embodiment, the program code for emulating a telephone-type keypad includes program code for emulating one or more different models of GSM, 3G, or CDMA cellular telephones produced by one or more different manufacturers. In one version of this embodiment, the type, manufacturer and model of the cellular telephone emulated is based on information stored in the VIM or SIM associated with the information processing device.
In still another aspect, the invention is directed to a computer program product for use in conjunction with a WLAN enabled information processing device. Generally, the computer program product includes a computer readable storage medium and a computer program mechanism embedded therein. The computer program mechanism has a program module that directs the information processing device, to function in a specified manner, to emulate a cellular communications terminal. The program module includes program code for: (i) emulating a telephone-type keypad; (ii) taking in information from the keypad; (iii) encapsulating information from the keypad into packets compatible with the access point of the WLAN; (iv) transmitting packets to establish a session with the access point; (v) taking in an audible signal or voice information from a microphone in or connected to the information processing device; (vi) encapsulating the voice information from the microphone into packets containing voice information or voice packets compatible with the access point of the WLAN; (vii) transmitting the voice packets to the access point; (viii) converting the voice packets received in the access point in to packets or signals compatible with the public network or private network; (ix) receiving voice packets from the access point; and (ix) converting the received voice packets into an audible signal or voice information to engage in voice communication with a telephone coupled to the private or public network.
In still another aspect, the invention is directed to a method of adapting a WLAN enabled device to emulate a cellular communications terminal. In the method, a telephone-type keypad is emulated on the information processing device and information taken in from the keypad. Information from the keypad is then encapsulated into packets compatible with the access point of the WLAN, and packets transmitted to establish a session with the access point or WLAN. An audible signal or voice information is taken in from a microphone integrated with or connected to the information processing device, and the voice information from the microphone encapsulated into packets or voice packets compatible with the access point of the WLAN. The voice packets are then transmitted to the access point. Voice packets from the access point are received and converted into an audible signal or voice information, thereby enabling the user to engage in voice communication with a telephone coupled to a private wireless network coupled to the WLAN.
Advantages of the apparatus and method of the present invention include any or all of the following:
(i) the ability to provide both wireless voice and data communication to a portable computer or PDA simultaneously;
(ii) less expensive, less complex, and lower weight or bulk than separate cellular telephone and portable computer combined;
(iii) compatible with standardized public network and Internet network infrastructures;
(iv) voice communication having a quality of service the same as or superior to that provided by single purpose GSM or 3G cellular telephones; and
(v) ability to provide high-speed high-bandwidth broadband connection to an existing public wireless network using WLAN technology.